Fix gcc builds failing on Windows

[Repiteo]

Addresses 3 seperate errors/failings that occured for me when trying to build on windows with mingw

platform\windows\gl_manager_windows.cpp: In member function 'void GLManager_Windows::_nvapi_disable_threaded_optimization()':
platform\windows\gl_manager_windows.cpp:118:32: error: cast between incompatible function types from 'FARPROC' {aka 'long long int (*)()'} to 'void* (*)(unsigned int)' [-Werror=cast-function-type]
  118 |         NvAPI_QueryInterface = (void *(__cdecl *)(unsigned int))GetProcAddress(nvapi, "nvapi_QueryInterface");
      |                                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

A define existed for wglGetProcAddress, but not GetProcAddress like most other Windows files; that's now fixed

platform\windows\display_server_windows.cpp: In member function 'virtual void DisplayServerWindows::set_icon(const Ref<Image>&)':
platform\windows\display_server_windows.cpp:2412:83: error: passing NULL to non-pointer argument 4 of 'LRESULT SendMessageA(HWND, UINT, WPARAM, LPARAM)' [-Werror=conversion-null]
 2412 |                 SendMessage(windows[MAIN_WINDOW_ID].hWnd, WM_SETICON, ICON_SMALL, NULL);
      |                                                                                   ^~~~

Typecasting the NULL values as (LPARAM)NULL fixed the errors

'C:/Tools/msys64/mingw64/bin/x86_64-w64-mingw32-objcopy' is not recognized as an internal or external command,
operable program or batch file.
'C:/Tools/msys64/mingw64/bin/x86_64-w64-mingw32-strip' is not recognized as an internal or external command,
operable program or batch file.
'C:/Tools/msys64/mingw64/bin/x86_64-w64-mingw32-objcopy' is not recognized as an internal or external command,
operable program or batch file.

Not technically an error, but .debugsymbols files weren't properly generating because objcopy and strip don't have any prefix. Passing an empty arch value returns the expected path but with no erroneous prefix

[bruvzg]

because objcopy and strip don't have any prefix.

In many cases they do, it depends on distribution, so code probably should try both and check if files exist.

[Repiteo]

In many cases they do, it depends on distribution, so code probably should try both and check if files exist.

Oh! Didn't realize that was a possibility, good to know; I'll adjust accordingly

[Repiteo]

Adjusting the Python to check for multiple files is a bit beyond the scope of what I expected to do this PR, so I'll leave the old version as-is considering it's functional on most distributions

[YuriSizov]

Thanks!